Mn = The nominal momentd = the depth of the concrete beam (note: that this is not the same as the height of the beam)

4. Compute the factored moment capacity (øMn):

Above in Section #2 it was determined whether or not the section is tension controlled. The results from Section #2 will determine what ø (reduction factor) you should use. This will then be compared to the factored moment you find acting on the beam.